Centralized traffic controlling system for railroads



H. P. OBER I 2,059,173

CENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Oct. 27, 1936.

Filed NOV. 22, 1933 l I l cosmgm Em iTuu t bcou Patented Oct. 27, 1936 PATENT OFFICE CENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Hermon P. Ober, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application November 22, 1933, Serial No. 699,202

13 Claims.

This invention relates to railway centralized traflic controlling systems, and more particularly to a system of the non-coded or direct control type, as distinguished from a selector type of system.

It is proposed in accordance with the present invention to provide a centralized traffic controlling system whereby a remote track switch and signals associated therewith may be controlled from a central point or control office, and whereby indications regarding the operating position of the switch and signals and the presence of a train in a certain track section may be transmitted to the control oifice. It is further proposed to reduce the number of line circuits ordinarily employed to efiect such transmission of controls and indications by utilizing one line circuit for the dual purpose of controlling the track switch and for indicating occupancy of an associatedtrack section, and to further reduce the number of line circuits by utilizing a second line circuit both to transmit an indication of the condition of the signals as well asan indication concerning the position of the track switch to the control ofiice. It is also proposed to provide at the remote location such interlocking of circuits as to prevent the execution of conflicting controls and which also permits the retaining of an existing'signal control in the event of a subsequent change in the position of the switch control means.

Other objects, purposes and characteristic features of the invention will appear as the description thereof progresses, during which references will be made to the accompanying drawing which illustrates in a diagrammatic and conventional manner one specific embodiment of the present invention, and which is susceptible of considerable modifications or adaptations in practice depending on the type of controls required and the character and number of indications which are considered advantageous in the particular application.

In the accompanying drawing, a complete communicating system is shown for transmitting controls and indications between a typical outlying field station and the apparatus at the control ofiice which is associated with this field station. In a practical application of this system, it will be apparent that there will be considerable distance between a field station and the control office and that it is necessary to extend only four line wires, namely, L L L and the common wire COM, over this distance. In systems having several outlying field. stations, 3

line wires such as L L and L will of course be required for each, and the field station appa-, ratus as well as the control ofiice apparatus which are designated by the legend on the drawing will also be duplicated for each of the outlying stations. It may be mentioned also that the wire COM may be the common wire for the complete centralized trafiijc controlling system if so desired, or may be of the common wire for one station only.

A portion of a track diagram which is associated with the typical section of track 'towhich the present invention is applied is diagrammatically shown in the accompanying drawing, and. an indicating light OS of the conventional type is provided therein and arranged to display an indication of the presence of a train in a particular track section. A signal control lever SGL is associated with the track diagram and arranged to operate to three positions W, S and E for setting up controls for wayside signals governing' traffic over the track switch. A switch control lever SML is also provided at the track diagram and is operable to either of two posi tions N and R for setting up controls for a switch machine employed to position a track switch in either its normal or reverse position as designated-by the two extreme positions N and R. Suitable contacts are shown in the conventional manner as operated to three distinct positions by the signal control lever SGL and similar contacts are operated to two positions by the switch control lever SML a signal clear indicating light SK is associated with the switch control lever SGL for the purpose of indicating when a wayside signal controlled thereby is displaying a clear indication, and a similar indicating light COR is associated with the lever SML for indicating when the operated position of the track switch controlled thereby is in correspondence with the position of this lever.

The section of track corresponding to the portion of the track diagram shown at the control ofiice is illustrated at the field station as including a. track switch TS arranged to route traffic over a main or diverging track. This track switch TS is operated by a switch machine SM which is in turn controlled by a two-position polar relay WZ. Suitable wayside signals ES, ESA, WS, WSA are shown in the conventional manner as governing trafiic'movements over the track switch TS and these signals are selectively cleared to govern trafiic movements with the direction determined by the energization of a polar neutral relay SZ.

Various other relays at both the control office and the field station are shown in the conventional manner, and it may be here mentioned that relay TK at the control ofiice is of the double winding type arranged so that one or the other of these windings is energized depending upon the position of the switch control lever SML and. by relatively opposite polarities but these windings are so arranged that the magnetism in the relay remains the same regardless of the polarity of energization and this energization is maintained during a change of position of thelever SML by an overlapping lever contact as shown. The indicating relay K at the control ofiice is of the conventional three-position polar type.

Relay M at the field station is the conventional signal repeating relay arranged in the local signalling circuits (not shown) to be normally energized whenever all the signals ES, ESA, WS and WSA are at stop but to be ie-energized whenever any one of these signals displays. a clear indication. The relay TR is the conventionally arranged track relay associated with a normally energized section of track including the track switch TS. The relay WP is a conventional switch repeating relay arranged to operate its polar contacts to position corresponding to the operated position of the track switch TS and to drop its neutral contact whenever the switch is not in either extreme locked position by circuits including point detector contacts such as shown in the patent to C. S. Bushnell, Pat. No. 1,517,236 granted November 25, 1924..

Relay LK is the conventional lock relay which may be controlled in any suitable manner so long as it looks the switch machine SM against operation whenever it is improper to operate the associated track switch TS or namely when a route has been cleared over this track switch or a route set up over this switch has been accepted by a moving train, but preferably this lock relay LK is controlled in a manner as a similarly designated lock relay in the prior application of R. M. Phinney, vSex. No. 463,940 filed June 26, 1930 is shown controlled. Although the relay LK may be controlled in any conventional manner, it has been illustrated as being associated with a stick relay S and a time release relay TE, which relays are associated with the detector track relay TR and the signals at stop relay M so as to render the relay LK deenergized whenever the signals are cleared and whenever the detector track section is occupied. When the locking relay LK is once deenergized, it remain deenergized until after the signals have been put to stop for a. predetermined time as measured by the time element device TE (control for which has not been shown) or until the passage of a train over the detector track section, as will be described hereinafter.

In pointing out the circuits throughout the description of the operation of the present system and will be considered opposite terminals of a source of energy at the control office and also of a similar source of energy located at the field station while (0) will be considered a central or intermediate tap for each of these energy sources. It is also to be understood that the common line wire COM is connected to this central tap (c) of both the control office source of energy and the field station source of energy.

Operation In the accompanying drawing, the track switch TS is shown in its normal position for routing traflic straight through on the main track in accordance with the normal position N of the switch control lever SML. The relay S is normally energized through a stick circuit from through front contact 3|, windings of relay S, front contact 30 of relay M, to With the relay S picked up, the relay LK is normally energized through a circuit closed from front contact 28 of relay TR, windings of relay LK, front contact 29 of relay S, to

It will now be considered in describing the oper-- ation of the system that an operator, desiring to reverse the track switch TS to route traffic on the passing siding, moves the switch control lever SML to the reverse position R thereby reversing the polarity on the switch control relay WZ at the field station over a circuit from through the upper winding of relay TK, contact 4 of lever SML in its reverse position, line wire L front contact 5 of relay TR, front contact 6 of relay LK, through the windings of relay WZ to (c) It will be considered that this polarity of energy causes current to flow from left to right through the winding of relay WZ thereby operating its polar contacts to their right hand position, which position is out of correspondence with the operated position of the track switch TS as reflected by the left hand position of the polar contacts of relay WP. This out of correspondence condition energizes relay K at the control ofiice over a circuit from contact I of relay WP in its left hand position, contact 8 of relay WZ in its right hand position, front contact 9 of relay M, line wire L through windings of relay K to (c). It will be considered this polarity of energy causes current to flow from right to left through the windings of relay K thereby operating its polar contact Ill to the left which energizes the indicating light COR over an obvious circuit to indicate that the position of the track switch TS is now out of correspondence with the position of its control lever SlVIL.

The right hand position of the polar contacts of relay WZ operates the switch machine SM to move the track switch TS to its reverse position over a circuit from front contact l3 of relay LK, neutral front contact M of relay WZ, polar contact I5 of relay WZ in its right hand position, reverse control wire RC and through operating mechanism of the switch machine SM to When the track switch TS assumes its reverse locked position, the polarity of energization of relay WP is obviously reversed, and contact l is moved to its right hand position which is then in correspondence with the right hand position of contact 8 of relay WZ, thereby deenergizing relay K at the control office which relay in turn de-energizes the indicating light COR to indicate that the track switch TS has assumed its reverse position in accordance with the reverse position of its control lever SML.

It may be mentioned here in connection with the track switch indicating circuit just described that in case the track switch becomes moved to an unlocked position for any reason the neutral back contact l6 of relay WP will obviously be closed to energize the relay K at the control office over a circuit similar to the indicating circontrol lever SML and the track switch although contact 1 of relay WP is in correspondence with contact 8 of relay WZ.

It'will now be considered that the operator moves the signal control lever SGL from its stop position S to its clear east bound position E to allow a train movement from the main track eastward onto the diverging track inasmuch as the switch TS is now in its reverse position. The relay SZ at the field station is then energized over a circuit from (a) through windings of relay SZ, line wire L contact I! of lever SGL in position E to It will be considered that this polarity of energy causes current to flow from right to left through the windings of relay S2 and thereby operates the polar contacts to their left hand position which position completes a circuit for energizing signal ESA which may be traced from front contact ll? of relay TR, front contact IQ of relay WP, polar contact 20 of relay WZ in its right hand position, polar contact 2| of relay WP in its right hand position, neutral front contact 22 of relay SZ, polar contact 23 of relay SZ in its left hand position and through the local signalling circuits to energize signal ESA as indicated by the dotted line 24.

It will be obvious that if the track switch TS were in its normal position, as shown, the left hand position of the polar contacts 20 and 2! of relay WZ and WP respectively would complete a very similar circuit to energize signal ES rather than ESA by virtue of the left hand position of polar contact 25 of relay S2, and it is not considered necessary to trace this circuit in detail. It will also be obvious that the clear west bound position W of signal lever SGL will apply a relatively opposite polarity of energy to relay S2 to position its polar contacts to the right and thereby allow either signal WS or signal WSA to clear depending upon the position of polar contacts 2|! and 2! of relay WZ and WP.

The clearing of any one of the signals ES, ESA, WS or WSA in accordance with the energization of relay SZ is effective to de-energize relay M as. previously described, which then completes an energizing circuit for relay K at the control office from (0) through the windings of relay K, line wire L back contact 9 of relay M to It will be considered that this polarity of energy applied to relay K being relatively opposite to the polarity applied thereto for switch-correspondence indication causes current to flow from right to left through its windings thereby operating its polar contact H3 to its right hand position, which position completes an obvious energizing circuit for the light SK to indicate that a signal at the field station is displaying a clear indication in accordance with a clear position of the signal control lever SGL.

The relay LK at the field station is now deenergized during the existence of a clear signal indication by reason of the deenergization of relay S because of open contact 30 of relay M, which relay S causes the deenergization of relay LK at its open front contact 29. This deenergization of the relay LK shifts the switch control circuit by back contact 6 of relay LK to exclude relay WZ and to include a suitable resistance RS to compensate for the resistance of the operating windings of relay WZ and thereby maintain a constant amount of current through the windings of relay TK at the control office. It is obvious that the. switch machine SM cannot respond to a change in position of the contacts of its control relay WZ when a signal is displaying a clear indication due to the open front contact 13 of relay LK but inasmuch as it is necessary to maintain correspondence between relays WZ and WP to obtain a clear signal, it has been considered expedient to remove the control of relay WZ from its control lever SML during the display of a clear signal indication. In other words, the opening of front contact 6 of relay LK during a clear signal indication maintains an existing correspondence between the position of polar contact 20 of the polar neutral relay WZ and polar contact 2| of relay WP even in the event of a movement of lever SML.

Considering now that a train accepts the clear indication displayed by signal ESA and enters the section of track including the switch TS, the relay TR will obviously be dropped to open the energizing circuit of relay TK at the control oifice at front contact 5 of relay TR, which relay TK was being energized through back contact 6 of relay LK and through resistor RS. The de-energization of relay TK energizes the indicating light OS through its back contact 21 to indicate that a train is now occupying the section of track at the field station including the track switch TS.

The passage of a train onto the detector track section deenergizing the relay TR, closes a pick up circuit for the relay S as soon as the signals go to stop in response to such track occupancy resulting in the picking up of the relay M. This pick up circuit is closed from through back contact 28 of relay TR, winding of relay S, front contact 30 of relay M, to front contact 3! of relay S closes the stick circuit for this relay so that it is maintained picked up so long as the signals are left at stop. Closure of front contact 29 of relay S together with the closure of front contact 28 of relay TR, assuming that the train has now passed beyond the detector track section, completes the energizing circuit for relay LK so that the relay W2 is again connected to its control circuit.

Although the relay S has thus been described as picked up on the passage of a train, it can also be picked up by the automatic operation of the timing device TE upon the return of the signals to stop in response to manual control of the relay SZ. In other words, when the signals are returned to stop the relay M is picked up and the timing device TE is automatically set into operation through means not disclosed, but which have been shown in the above mentioned application of R. M. Phinney, Ser. No. 463,940,

7 filed June 26, 1930. This automatic operation of the timing device TE closes an auxiliary pick up circuit for relay S including the contact of relay TE and front contact 36 of relay M. This provides a release for the lock relay LK in the event that a train does not pass over the detector track section.

A railway centralized trafiic controlling system has thus been provided which permits the control of a distant track switch as well as the signals associated therewith and also permits an indication to be transmitted from this remote location to the control point concerning the response of the track switch and signals to their transmitted controls as well as concerning the occupancy of an associated track section.

A considerable amount of line Wire has been saved in the transmission of the above named controls and indications by multiplying the use of certain line circuits, and attention is further directed to the means by which the switch control leveris rendered ineifective to interrupt an existing clear signal and although this means excludes the switch control relay from its control circuitv this control circuit is maintained ener gized through a second circuit at the field station The closure of to permit an indication concerning track occupancy to be transmitted to the control ofilce thereover.

The above rather specific description of one form of the present invention is given solely by the way of example, and is not intended in any manner whatsoever in a limiting sense. It is also to be understood that various modifications, adaptations and alterations may be applied to meet the requirements of practice, without in any manner, departing from the spirit or scope of the present invention except as limited by the appended claims.

Having thus described my invention, what I claim is:

1. A railway centralize-d traffic controlling system having, in combination, a control office, a field station, a track switch and associated signals at the field station, two line circuits connecting the control ofiice and the field station, a switch control means at the field station positioned in accordance with the polarity of energy applied at the control ofiice to a first of said line circuits only when the signals are displaying a most restricted indication, signal control means at the field station operable to allow the signals to display a less restricted indication in accordance with the polarity of energy applied at the control ofiice to a second of the line circuits only when the position of the track switch corresponds to the position of said switch control means, and means for at all times indicating at the control ofiice entirely over the first of the line circuits the occupied or unoccupied condition of a section of track at the field station.

2. In combination, a control ofiice, a field station, three line circuits connecting the control oifice and the field station, a track switch and associated signals at the field station, a signal controlling relay at the field station responsive to the energization of a first of the line circuits, :1 switch controlling relay at the field station responsive to the energization of a second of the line circuits only when the signals are displaying a most restricted indication, means shifting the second line circuit to exclude the switch controlling relay without deenergizing said second line circuit when the signals are displaying a less restricted indication, means deenergizing the second line circuit during the presence of a train on a section of track including the track switch, an indicating relay at the control ofiice responsive to the deenergization of the second line circuit, and means for indicating at the control ofiice the condition of both the track switch and associated signals over a third of the line circuits.

3. In combination, a control ofiice, a field station, three line circuits connecting the control ofiice, a track switch and signal associated therewith at the field station, a three position signal control lever at the control ofiice arranged to selectively energize a first of the line circuits, a signal control relay at the field station operable to three positions in accordance with the energization of the first line circuit and governing said signal in accordance therewith, atwo-position witch control lever at the control office operable to select the polarity of energization of a second of the line circuits, a relay at the control office responsive to the energization of the second line circuit but not responsive to a change in polarity of energization thereof, means de-energizing the second line circuit during the presence of a train on the track switch, a switch control relay at the field station operable to either of two positions in accordance with the energization of the second line circuit, means permitting the display of a clear signal indication only when the position of the track switch corresponds to the position of the switch control relay, means shifting the second line circuit to exclude the switch control relay without deenergizing said second line circuit when said signal is cleared for allowing the passage of traffic over said track switch, means at the field station applying one polarity of energy to a third of the line circuits when the position of the track switch does not correspond to the position of the switch control relay, means for applying another polarity of energy to the third line circuit when a clear signal indication is being displayed at the field station, and a three position indicating relay at the control ofiice responsive to the polarity of energy of the third line circuit.

4. A railway traffic control system having, in combination, a control ofiice, a field station, three line wires connecting the control office and the field station, means including one of the line wires for at all times controlling signals at the field station from the control office, means including a second line wire for at times controlling a track switch at the field station from the control ofiice, means including the second line wire for at all times indicating at the control office the presence or absence of a train in a section of track at the field station, and means including the third line wire for indicating at the control office either the condition of said track switch or said signals depending upon whether said signals are at stop or clear.

5. In combination; a railroad track switch; a switch machine for operating said track switch; a control lever; a switch machine control relay adjacent said switch machine; an indication relay adjacent said control lever; circuit means including said indication relay, said lever and said switch control relay in a series circuit; one means for at times excluding said switch control relay from said series circuit without deenergizing said indication relay, and other means for at times deenergizing said indication relay irrespective of whether said switch control relay is included or excluded, whereby said indication relay is controlled in accordance with said other means and is unaffected by said one means.

6. In combination, a switch machine for operating a railroad track switch, a central oflice, a line circuit connecting said central ofiice and said track switch, a switch machine control relay at times included in said line circuit and responsive to the direction of current flow in such circuit, a control lever at said central ofiice for applying energy of one polarity or the other to said line circuit whereby said circuit is energized irrespective of the inclusion or exclusion of said switch machine control relay, an indication relay at said central ofiice included in said line circuit responsive to the energization thereof but unresponsive to a change in the polarity of current as applied to said circuit by said control lever, and other means for at times opening said line circuit, whereby said indication relay is controlled by said other means but is unafiected by the inclusion or exclusion of said switch machine control relay.

'7. In combination, a switch machine for operating a railroad track switch, a central office, a line circuit means connecting said central office and the track switch location including a plurality of contacts only one contact of which can open said circuit, a switch machine control relay at times included in said line circuit means and.

responsive to the direction of current flow in such circuit, a control lever at said central oiiice for operating another of said contacts for reversing the direction of current flow in said line circuit means, an indication relay at said central ofiice responsive to the energized or deenergized condition of said line circuit means but unaffected by a reversal of direction of current flow therein, and other means for controlling said one contact to at times open said line circuit means, whereby said indication relay is controlled only by said other means.

8. In combination, a switch machine for operating a railroad track switch, signals operable to clear or stop conditions for governing traiiic over the track switch, a central office, a linecircuit connecting said central ofiice-and the switch location, a switch machine control relay, a compensating resistor, means inserting said switch control relay in said line circuit when said signals are at stop and inserting said compensating resistor in said circuit when said signals are cleared, whereby said circuit is unaffected by the change in condition of said signals, a control lever at said central office for reversing the direction of current flow in said line circuit, an indication relay at said central ofiice responsive to the energized or deenergized condition of said line circuit but unresponsive to a reversal of direction of current flow therein, a track relay for indicating the presence and absence of trafiic over said track switch, means opening said line circuit when said track relay indicates the presence of traflic, whereby said indication relay indicates the presence or absence of traffic at all times.

9. In combination, a switch machine for operating a railroad track switch to normal and reverse positions and locking the track switch in such positions, signals operable to clear or stop for governing traflic over the track switch, a polarized indication relay, a switch control relay for governing the operation of said switch machine to normal or reverse positions, means for energizing said indication relay with one polarity when said track switch is unlocked or out of correspondence with said switch control relay only if said signals are at stop, and means for energizing said indication relay with the opposite polarity whenever said signals are cleared.

10. In combination, a switch machine for operating a railroad track switch to normal or reverse positions and locking the track switch in such positions, a polarized indication relay, a switch control relay for governing the operation of said switch machine to normal or reverse positions, signals operable to clear or stop only when said switch control relay and said track switch are in corresponding positions for governing traffic over the track switch, means for energizing said indication relay with one polarity when said track switch is unlocked or is out of correspondence with said switch control relay but only when said signals are at stop, and means for energizing said indication relay with the opposite polarity whenever said signals are cleared.

11. In combination, a switch machine for operating a railroad track switch to normal and reverse positions and locking the track switch in such positions, signals operable to clear or stop for governing traific over the track switch, a polarized indication relay, a switch control relay for governing the operation of said switch machine to normal or reverse positions, means for energizing said indication relay with one polarity only when said track switch is unlocked or out of correspondence with said switch control relay and said signals are at stop, means for energizing said indication relay with the opposite polarity whenever said signals are cleared, and indication means controlled by said indication relay to indicate the correspondence or noncorrespondence of the track switch with said control relay and the clear or stop condition of the signals.

12. In combination, a switch machine for operating a railroad track switch, a polarized control relay for governing the operation of said switch machine, a two-position switch control lever, a line circuit connecting said switch control lever and said control relay and having one polarity or the other applied thereto depending upon the position of said control lever, an indication relay included in said line circuit so as to be responsive to the energized and deenergized condition of said line circuit but unaffected by a quick reversal of the polarity applied thereto, means for at times rendering said control relay unresponsive to said control lever over said line circuit without affecting the condition of energization of said line circuit, and a detector track relay associated with the track switch for at times opening said line circuit, whereby said indication relay is under the direct control of said detector track relay.

13. In combination; a switch machine for operating a railroad track switch; a polarized control relay for governing the operation of said switch machine; a two-position switch control lever; a line circuit connecting said switch control lever and said control relay and having one polarity or the other applied thereto depending upon the position of said control lever; an indication relay; means connecting said indication -relay in said line circuit in one direction or the other depending upon the position of said control lever, whereby said indication relay is responsive to the energized and deenergized condition of said line circuit but is unaffected by a reversal of the polarity applied thereto by said lever; means for at times rendering said control relay unresponsive to said control lever over said line circuit without affecting the condition of energization of said line circuit; a detector track relay associated with the track switch for at times opening said line circuit; and an indicator controlled by said indication relay; whereby said indicator is under the direct control of said detector track relay.

HERMON P. OBER. 

